The Douglas A-26 Invader is a twin-engined light bomber and attack aircraft that was built by Douglas Aircraft Company during World War II which also saw service during several major Cold War conflicts. A limited number of highly modified United States Air Force aircraft served in Southeast Asia until 1969. A range of guns could be fitted to produce a formidable ground-attack aircraft. It were powered by the widely used Pratt & Whitney R-2800 Double Wasp eighteen-cylinder, double-row radial engine. The last A-26 in active U.S. service was assigned to the Air National Guard; that aircraft being retired from military service in 1972 by the U.S. Air Force and the National Guard Bureau and donated to the National Air and Space Museum.